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Homemade Coil Spring Compressor

Since I feel like I will be undertaking a potentially dangerous task, I
thought I would first ask the experts on this group. For replacing the
trailing arm on my car, I need to compress the coil spring. I have
already removed the shock absorber from the middle of the spring so
have room work inside the center of the spring.

I purchased a pair of external "hook type" compressors which are
designed to be used on each side of the spring but now I am having
second thoughts about using them. The hooks appear to made from cast
metal and do not appear to be drop forged steel. The width of the
hooks is also thinner than I would like and am concerned that one of
these hooks could crack under tension with disastrous results. For
this reason, I would feel alot safer making my own.

The idea I had would be to use a 10" piece of 5/8" allthread rod (the
kind normally found at Home Depot or Lowe's) and two 1/4" mild steel
plates with a center hole drilled slightly larger than 5/8". To use I
would feed the threaded rod up inside the middle of the coil (where the
shock used to go) through each one of the steel end plates secured with
bolts and washers. The diameter of the spring is approx. 4.5" and the
end plates would measure 2"x8" so there would be 1.75" of overhang on
each side of the coil. Would 5/8" rod be strong enough for this
application or would I be better off using 3/4" rod? Also is 1/4" mild
steel ok or do I need to use something thicker?

"T.C. Mann" wrote in message
oups.com...
Since I feel like I will be undertaking a potentially dangerous task, I
thought I would first ask the experts on this group. For replacing the
trailing arm on my car, I need to compress the coil spring. I have
already removed the shock absorber from the middle of the spring so
have room work inside the center of the spring.

I purchased a pair of external "hook type" compressors which are
designed to be used on each side of the spring but now I am having
second thoughts about using them. The hooks appear to made from cast
metal and do not appear to be drop forged steel. The width of the
hooks is also thinner than I would like and am concerned that one of
these hooks could crack under tension with disastrous results. For
this reason, I would feel alot safer making my own.

The idea I had would be to use a 10" piece of 5/8" allthread rod (the
kind normally found at Home Depot or Lowe's) and two 1/4" mild steel
plates with a center hole drilled slightly larger than 5/8". To use I
would feed the threaded rod up inside the middle of the coil (where the
shock used to go) through each one of the steel end plates secured with
bolts and washers. The diameter of the spring is approx. 4.5" and the
end plates would measure 2"x8" so there would be 1.75" of overhang on
each side of the coil. Would 5/8" rod be strong enough for this
application or would I be better off using 3/4" rod? Also is 1/4" mild
steel ok or do I need to use something thicker?

Thanks for your help.

Personally I would trust the ones you bought, provided they were sold and
designed for the task at hand and were bought from a reputable dealer. I say
this with 12 years experience as an ASE certified auto mechanic who worked
in a few different shops with different tools for compressing auto coil
springs. I've probably replace a few hundred strut shocks in that time.